PCB is a substrate for installing and connecting various different electronic elements to accomplish a selected effect through interconnection of the different electronic elements. The most commonly used PCBs are main board, VGA card, wireless network card and the like. The commonly used electronic elements on the PCBs include chip set, capacitor, inductor, resistor and the like. Some of those electronic elements are mounted onto the PCB by surface mount technology (SMT), such as SMT elements; while some others are mounted onto the PCB by wave soldering, such as pin elements.
Wave soldering mainly employs a pump to generate an elongated tin wave on the surface of molten liquid-state tin in a tin oven, and the PCBs are carried by a conveyor belt in an inclined manner to pass over the tin oven to allow the liquid-state tin to be filled in the pin inlets of connection pin elements to form soldering points. The carrier holding the PCBs to pass over the tin oven for wave soldering is generally called frame fixture.
Refer to FIG. 1 for a conventional frame fixture 10. It is a rectangular structure consisting of four sides 12 and an opening 14 in the center. Each side 12 has a flange 16 extended from an inner edge. The edge of a PCB 18 may be rested on the flange 16 of each side 12. The upper surface of each side 12 has a plurality of clamp mechanisms 20 to apply a downward pressure on the upper surface of the PCB 18 so that the PCB 18 may be held and anchored firmly on the frame fixture 10.
However, the PCBs of different specifications have different shapes and sizes. In order to match different types of PCBs, the size of the frame fixture also should be changed. Due to the shape and size of conventional frame fixtures are not adjustable, once the specification of the PCB changes, the original frame fixture becomes useless.
Hence it becomes a waste of material of the frame fixture. Especially in the test stage of PCB design, the specification and dimension of the PCB frequently change for various reasons. As a result, the frame fixture for the PCB also has to change at the same time. Moreover, remaking the frame fixture takes a lot of time. In short, the dimension of the present frame fixture cannot be adjusted to match different specifications of PCBs, and results in waste of time and material resources.